A post-apocalyptic adventure split between two character perspectives, the plots here move forward quickly and in parallel, as a couple separated following a 50-year frozen sleep by which they escaped the destruction seeks to survive and perhaps reunite. The end of the world comes in a ball of fire. Wren is so not ready, who would be? As she races to the shelter of the cryobanks she has only one thought on her mind, survival. It's a different story once she awakes fifty years later. In the aftermath of the solar flare that has hit the earth in all of its raging fury, Wren must join her squad to find her way back to civilization. She has lost everything and, as she grieves the death of her mother and the boy who loved her better than she deserved, she finds comfort in her new friend Ian. She hopes that the promise of a future with him is enough to keep her going. Aiden arrives at the government hub shortly after he awakes in his cryotube. He has one thought, to find Wren and get her through the wild safely. He gets his chance when Commander Rob assigns him to a mission back out in the demolished gray terrain. He has already made the decision to go out on his own once the mission is complete. He has to find the love of his life and make everything right before he can move on. But when he sees the senseless murder of the survivors in the wild, all at the hands of the new government, he knows that he won't come back. He will find a new life in the Underground, fighting with the rebels to take back what is left of the world. He only hopes that Wren will be by his side. Much care is put into the characters than many books of its ilk. The disconnect between the two protagonists--one still carries a flame, one still carries regret--is compelling, and the emotional anguish of characters in a sinister and traumatizing position is realized effectively.